Check, Clean, Dry - Why every wild swimmer should think about biosecurity by Sara Barnes

Lake District writer and wild swimmer Sara Barnes explains the importance of biosecurity.

Most people want to be responsible when they visit beautiful, pristine places, but they need to know how and why

The word ‘biosecurity’ may conjure up Dr Who-like figures in white boiler suits and Perspex face shields, but it is far more insidious than that, far more nightmarish and important. In human terms it can be defined as: procedures or measures designed to protect the population against harmful biological or biochemical substances.

In the world of water the best way to explain it is: Biosecurity refers to measures aimed at preventing the introduction and/or spread of harmful organisms to animals and plants in order to minimise the risk of transmission of infectious disease. However, sadly, such measures are often scanty, poorly signposted and frankly, misunderstood and ignored by too many institutions and people. It is indeed hard to imagine how just one tiny piece of vegetation stuck onto the bottom of your paddle board, kayak, fishing line, wetsuit, towfloat, dog or inflatable dinghy could cause an issue once immersed in a body of water. But, imagine for a moment, you are that piece of slightly dried out weed, you know your days are numbered the moment you get pulled out of your usual lake, but you cling on anyway, because rumour has it that soon you’ll be back in the water, and even more exciting, somewhere new, somewhere you’ve not been before! Fresh, clean, clear water, where you can spread your wings and become the giant you know you are meant to be.

 Derwent Water Lake District Pygmy Weed

New Zealand Pygmy Weed at Derwent Water - Credit Sara Barnes

And, this is exactly what happens on a daily basis where I live: the Lake District. All it takes is one tiny strand of New Zealand Pygmy Weed (the invasive species which is currently causing the majority of the problems here) to be introduced to a new body of water and within minutes it will be fully rehydrated and ready for action. It will grow quickly in its new home and with time become an impenetrable mat of weed that is impossible to remove.  Non-native invasive species, such as New Zealand Pygmy Weed (Crassula helmsii), also known as Australian swamp stonecrop) was first introduced into Derwent Water around 25 years ago when someone emptied their fish tank into the lake. The weed had been sold to aquarium owners in the UK from 1911 as an effective oxygenating plant, but its use has since been banned. I can hear people say, but if its job is to oxygenate then surely it’s a good thing? In a contained environment such as a glass fish tank its true horror does not show itself, but let loose into a huge body of water, such as a nutrient rich, relatively warm, lake, native species of plants and fish do not stand a chance against this voracious guzzler of nutrients. Within the time that I have lived in the Lake District and swum in Derwent Water (from around 1995) I have witnessed its clean and clear waters become the murky, weed-ridden place they are now. Up until about 10 years’ ago, I could dive down and see my hands in front of my face, now my hands catch pieces of the weed at every stroke and I can feel clumps of it tickling my legs if I swim in certain areas of the lake.

Crummock Water Lake District
Crummock Water in the Lake District. Credit Sara Barnes.

More disturbing news: Crummock Water, up until last summer to my knowledge, has stayed Pygmy Weed free, but when I saw the first signs of blue green algae I knew it had arrived. This once wild and remote lake’s fate is now sealed. I’m heart broken that the message is being broadcast too late, education needed to be stepped up over ten years ago. Contrary to what we are fed by the media, most people want to be responsible when they visit beautiful, pristine places, but they need to know how and why. The why is simple: I’m sure you’ve seen signs warning of the dangers of blue green algae to dogs and humans? Lurking behind the spread of the algae - New Zealand Pygmy Weed. Evidence suggests that the two are linked, which explains how I knew the weed had reached Crummock Water - and then I found not so tiny pieces of it in certain areas of the lake.

Check, Clean, Dry: three vital steps to remember every single time you enter or leave a new body of water anywhere in the country, not just the Lake District.

The how is to keep your gear and yourself clear of invasive species by thinking to yourself (and telling others) three words: Check, Clean, Dry: three vital steps to remember every single time you enter or leave a new body of water anywhere in the country, not just the Lake District. And if you travel abroad take a moment to reflect on this message too. Is your kit clean? As swimmers, how can we behave in a way that will give us confidence we are doing everything we can? New Zealand Pygmy Weed loves damp, warm places, such as folds in your wetsuit, around the waist belt on your tow-float, in your scrunched up swimsuit, the lining of your swim shoes and on parts of your body! Check everything you took into the water with you, pull off any tiny bits of greenery and leave them to shrivel up in the sun or air, rinse your gear in the lake and check again. When you get home rinse your kit with the garden hose, or in a bucket, but never pour the rinse water down the sink. Always throw it outdoors into the garden. If it goes down the sink or drain it will be an opportunity for any vegetation to survive and work its way back into a natural body of water. And talk about what you do with other swimmers; share this information with other lake users you meet. It’s not about telling people off; it’s about educating as many people as possible and potentially reducing the risk of another lake effectively dying in our lifetimes.

Sara Barnes immersed in water in the Lake District

You can find Sara on Instagram @bumblebarnes

Her book The Cold Fix, which explores the question ‘What is it about the cold water that people crave?’ is to be published by Vertebrate Publishing in early November 2022.

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